Ledaal Kebok Coren has been a demon-blooded dragon-blood with magic demon storm powers since the 1e DB hardcover; material that claimed things like "You can't be a demon-blooded dragon-blood with magic demon storm powers because Exaltation burns those away!" post-dates her, and seems largely to have been written by people with oWoD experience who thought it was their job to stomp down on vampire-werewolf hybrid abominations and the munchkins who want to play them. This is Exalted, though, and Ledaal Kebok Coren has always been cool, so we're running with her.
(A given Exalt's powers are already so diverse there's no real harm in letting someone diversify a bit more, provided they're paying XP for the Charms. Also, "I make it storm when I'm angry" isn't super game-breaking.)